Temperature Measurement in Microfluidic Systems Using Photobleaching of a Fluorescent Slab

2008 ◽  
Author(s):  
Lin Gui ◽  
Carolyn L. Ren
Keyword(s):  
Temperature Distribution ◽  
Temperature Measurement ◽  
Rhodamine B ◽  
Fluorescent Dye ◽  
Measured Temperature ◽  
Pdms Layer ◽  
Temperature Dependent ◽  
Buffer Solution ◽  
Fluorescent Intensity ◽  
Dye Diffusion

Temperature control is key to microfluidic-based Lab-on-a-Chip devices for a variety of applications such as polymerase chain reaction for DNA amplification and isoelectric focusing for protein separation where pH gradients are thermally generated. The most widely used temperature measurement method involves the mixing of the buffer solution with a fluorescent dye, which has a temperature-dependent fluorescent intensity. The temperature distribution in the liquid can be obtained by monitoring the fluorescent intensity distribution in the channel. However, this method can not be easily applied to polymer-made microfluidic chips because of dye absorption and penetration into polymer chips, electrophoresis of dye which causes artificial temperature gradients, and inevitable photobleaching of fluorescent dye. Therefore, a novel method is developed and presented here for temperature measurement by utilizing photobleaching of fluorescent dye. This method includes two novel contributions: i) a specially developed model for converting temperature-dependent photobleaching speed distribution to temperature distribution, and ii) an introduction of a thin polydimethylsiloxane (PDMS) layer with saturated Rhodamine B for solving the above-mentioned dye diffusion and electrophoresis problems. In this new method, a thin PDMS layer saturated with Rhodamine B is bonded with another PDMS layer with microchannels instead of mixing the dye with the buffer solution. Therefore, the problems associated with dye diffusion into PDMS chips and electrophoresis when an electrical field is applied to channels are avoided. The developed theory is validated by comparing the experimentally measured temperature distribution with numerical predicted results. The theory and its validation will be presented and discussed.

Whole Chip Temperature Measurements Using Thin-Film PDMS/Rhodamine B for Microfluidic Chip Design

2008 ◽  
Author(s):  
Razim Samy ◽  
Tomasz Glawdel ◽  
Carolyn Ren
Keyword(s):  
Thin Film ◽  
Temperature Field ◽  
Temperature Measurement ◽  
Rhodamine B ◽  
Microfluidic Devices ◽  
Temperature Measurements ◽  
Working Fluid ◽  
Pdms Layer ◽  
Fluorescent Intensity ◽  
Chip Temperature

A novel method for in-situ temperature measurements of microfluidic devices using thin-film poly(dimethylsiloxane) (PDMS) saturated with Rhodamine B dye is reported. Rhodamine B, a dye with temperature dependent fluorescent intensity, is frequently injected into the working fluid for on-chip temperature field visualization of glass and silicon based microfluidic devices. However, such a visualization method results in unreliable temperature measurements due to high absorption and adsorption for polymeric devices such as PDMS. Thus, an inexpensive temperature measurement technique is developed in which a thin PDMS layer (∼30 μm) is fabricated and submersed for several days into a Rhodamine B solution. To prevent backward diffusion of the dye into the working fluid during operation, a glass barrier (∼150 μm) is bonded between the thin film and the PDMS mold containing the microchannel design of interest. Temperature measurements are made by utilizing standard method of measuring changes in the normalized fluorescent intensity. For verification purposes, a new calibration curve is developed and the thin film is tested with a microchannel subjected to joule heating. The resulting temperature field along the axial direction of the channel for different applied powers compares well with numerical simulations. Analysis of dye intensities before and after experiments provides temperature deviation estimates due to photobleaching. Errors in temperature measurement due to the film thickness are discussed.

Whole Chip Temperature Measurements Using Thin-Film PDMS/Rhodamine B for Microfluidic Chip Design

2007 ◽  
Author(s):  
Razim Samy ◽  
Tomasz Glawdel ◽  
Carolyn Ren
Keyword(s):  
Thin Film ◽  
Temperature Field ◽  
Temperature Measurement ◽  
Rhodamine B ◽  
Microfluidic Devices ◽  
Temperature Measurements ◽  
Working Fluid ◽  
Pdms Layer ◽  
Fluorescent Intensity ◽  
Chip Temperature

A novel method for in-situ temperature measurements of microfluidic devices using thin-film poly(dimethylsiloxane) (PDMS) saturated with Rhodamine B dye is reported. Rhodamine B is commonly injected into the working fluid for on-chip temperature field visualization of glass and silicon based microfluidic devices since its fluorescent intensity is temperature dependent. However, such a visualization method results in unreliable temperature measurements for polymeric devices such as PDMS due to high absorption and adsorption. Thus, an inexpensive temperature measurement technique was developed in which a thin PDMS layer (∼30 μm) is fabricated and submersed for several days into a Rhodamine B solution. To prevent backward diffusion of the dye into the working fluid during operation, a glass barrier (∼150 μm) is bonded between the thin film and the PDMS mold containing the microchannel design. Temperature measurements are made by utilizing standard method of measuring changes in the normalized fluorescent intensity. For verification purposes, a new calibration curve is developed and the thin film is tested with a tapered microchannel subjected to joule heating. The resulting temperature field along the axial direction of the channel for different input power compares well with numerical simulations. Errors in temperature measurement due to the current design are discussed.

Temperature Measurement in Microfluidic Systems Using a Temperature-Dependent Fluorescent Dye

2001 ◽  
Vol 73 (17) ◽  
pp. 4117-4123 ◽  
Author(s):  
David Ross ◽  
Michael Gaitan ◽  
Laurie E. Locascio
Keyword(s):  
Temperature Measurement ◽  
Fluorescent Dye ◽  
Microfluidic Systems ◽  
Temperature Dependent

3.3μm Pyrometry In Single Sided Rta From 400–700°C Using In-Situ Measurement Of Reflection And Transmission

1997 ◽  
Vol 470 ◽  
Author(s):  
D. L. Marcy ◽  
S. Chial ◽  
M. Beneš ◽  
J. C. Sturm
Keyword(s):  
Temperature Measurement ◽  
A Priori ◽  
Measured Temperature ◽  
Temperature Dependent ◽  
Reflection And Transmission ◽  
Accurate Temperature ◽  
Heavily Doped ◽  
Accurate Temperature Measurement ◽  
Initial Results

ABSTRACTPyrometry of silicon wafers under 700°C at wavelengths over 1μm is difficult because lightly doped wafers become partially transparent. In this work, a modified commercial RTCVD reactor with 8” wafer capability was used to study the temperature measurement of Si wafers over the range of 400–700°C using top and bottom pyrometric detectors. We present initial results on measurements of both reflection and transmission in-silu to determine emissivity at 3.3μm. For heavily doped wafers emissivity was independent of temperature and the measured temperature by pyrometry agreed well with that measured by thermocouple for 400–700°C. For lightly doped wafers, emissivity was temperature dependent due to the increased transparency of the wafer at low temperatures. Using fixed emissivity, the measured temperature severely underestimates the actual temperature below 550°C. By calculating emissivity from the measured reflection and transmission, accurate temperature measurement was achieved from 400–700°C without any a priori knowledge of the wafer.

Two-Dimensional Temperature Measurement in Free Boundary Environment by Using Moiré Deflectometry With Monochrome LED Lamp

2013 ◽  
Author(s):  
Chien-Chih Chen ◽  
Ying-Yan Wu ◽  
Chen-Ching Ting
Keyword(s):  
Temperature Distribution ◽  
Free Boundary ◽  
Temperature Measurement ◽  
Low Cost ◽  
Vertical Wall ◽  
Ccd Camera ◽  
Laser Printer ◽  
Measured Temperature ◽  
Two Dimensional ◽  
Moiré Deflectometry

This article develops low cost moiré deflectometry for two-dimensional temperature measurement in free boundary environment. Experimental setup uses a red monochrome LED lamp with wavelength range of 625–635 nm as light source. In process, the light first runs through the convex lens and then propagates to the parabolic mirror with diameter of 406 mm and f/4.5 for generating the parallel light. The parallel light further propagates to test object and through two gratings with both pitch 254 lpi which are printed by laser printer. Behind the two gratings, a CCD camera is applied to capture the image, the distorted fringes. Based on the moiré deflectometry theory, the two-dimensional temperature distribution in free boundary environment can be determined in terms of the captured fringe shift analysis. This work has successfully measured the two-dimensional temperature distribution in free boundary environment with heat source models of 40–95 °C vertical wall, 60 W light bulb, and burning candle flame. The measured temperature deviations between moiré deflectometry and thermocouple thermometer are all less than 5%.

Real-time temperature measurement of living cells exposed to microwaves using a temperature-dependent fluorescent dye

2021 ◽  
Vol 547 ◽  
pp. 111190
Author(s):  
Guofu Dong ◽  
Wei Lu ◽  
Xuelong Zhao ◽  
Xue Guan ◽  
Yunlong Ji ◽  
...  
Keyword(s):  
Temperature Measurement ◽  
Real Time ◽  
Living Cells ◽  
Fluorescent Dye ◽  
Temperature Dependent

A Monochrome Light-Emitting Diode Moiré Deflectometry Technique for Two-Dimensional Temperature Measurement

2014 ◽  
Vol 136 (10) ◽  
Author(s):  
Jing-Nang Lee ◽  
Chien-Chih Chen
Keyword(s):  
Temperature Distribution ◽  
Free Boundary ◽  
Temperature Measurement ◽  
Light Emitting Diode ◽  
Vertical Wall ◽  
Laser Printer ◽  
Measured Temperature ◽  
Two Dimensional ◽  
Light Emitting ◽  
Moiré Deflectometry

This article develops low cost moiré deflectometry for two-dimensional temperature measurement in free boundary environment. Experimental setup uses a red monochrome light-emitting diode (LED) lamp with wavelength range of 625–635 nm as light source. In process, the light first runs through the convex lens and then propagates to the parabolic mirror with diameter of 406 mm and f/4.5 for generating the parallel light. The parallel light further propagates to test object and through two gratings both with pitch of 254 lpi which are printed by laser printer. Behind the two gratings, a CCD camera is applied to capture the image, the distorted fringes. Based on the moiré deflectometry theory, the two-dimensional temperature distribution in free boundary environment can be determined in terms of the captured fringe shift analysis. This work has successfully measured the two-dimensional temperature distribution in free boundary environment with heat source models of 40–95 °C vertical wall, 60 W light bulb, and burning candle flame. The measured temperature deviations between moiré deflectometry and thermocouple thermometer are all less than 5%.

Electrothermal analysis of integrated circuits: a realization by infrared thermography

2021 ◽  
Author(s):  
Farnoos Farrokhi
Keyword(s):  
Temperature Distribution ◽  
Integrated Circuits ◽  
Power Dissipation ◽  
Electronic Device ◽  
Power Measurement ◽  
Device Under Test ◽  
Distribution Analysis ◽  
Ir Thermography ◽  
Temperature Dependent ◽  
Run Time

The International Technology Roadmap for Silicon (ITRS) predicted that by the year 2016, a high-performance chip could dissipate as much as 300 W/cm² of heat. Another more noticeable thermal issue in IC's is the uneven temperature distribution. Increased power dissipation and greater temperature variation highlight the need for electrothermal analysis of electronic components. The goal of this research is to develop an experimental infrared measurement technique for the thermal and electrothermal analysis of electronic circuits. The objective of the electrothermal analysis is to represent the behavior of the temperature dependent characteristics of electronic device in near real work condition. An infrared (IR) thermography setup to perform the temperature distribution analysis and power dissipation measurement of the device under test is proposed in this reasearch. The system is based on a transparent oil heatsink which captures the thermal profile and run-time power dissipation from the device under test with a very fine degree of granularity. The proposed setup is used to perform the thermal analysis and power measurement of an Intel Dual Core E2180 processor. The power dissipation of the processor is obtained by calculating and measuring the heat transfer coefficient of the oil heatsink. Moreover, the power consumption of the processor is measured by isolating the current used by the CPU at run time. A three-dimensional fininte element thermal model is developed to simulate the thermal properties of the processor. The results obtained using this simulation is compared to the experimental results from IR thermography. A methodology to perform electrothermal analysis on integrated circuits is introduced. This method is based on coupling a standard electrical simulator, which is often used in the design process, and IR thermography system through an efficient interface program. The proposed method is capable of updating the temperature dependent parameters of device in near real time. The proposed method is applied to perform electrothermal analysis of a power MOSFET to measure the temperature distribution and the device performance. The DC characteristics of the device are investigated. The obtained results indicated that the operating point, I-V characteristics and power dissipation of the MOSFET vary significantly with temperature.

Sign in / Sign up

Export Citation Format

Share Document